1. Field of the Invention
This invention relates in general to production of oil and gas wells, and in particular to a device and method for deploying a riser subsea. More particularly, the present invention relates to parking a riser subsea and moving the riser to an adjacent wellhead for wellhead operations.
2. Description of Related Art
Subsea risers are tubular members extending from the sea surface to seafloor. One option when encasing a drill string during drilling a well subsea, a riser typically spans between a drilling rig to a subsea wellhead mounted on the seafloor. The riser usually remains coupled to the subsea wellhead until after the well is completed. Fluids produced from the well generally flow from the wellhead into a flow line that discharges into a manifold connected to flow lines from other wellheads. Fluids converging in the manifold are delivered to above the sea surface via a main flow line. Over time, a producing well typically undergoes maintenance or workover procedures that require a riser be reconnected to the wellhead, this is usually a smaller diameter that can act as a conduit for wellbore fluids during well testing or a conduit for tools and gauges etc during well workover operations, so that the well can be accessed from above the sea surface. During such maintenance procedures the riser can be connected to drilling rig or a surface vessel on its upper end. In either instance, the riser is redeployed from a storage site or manufacturing facility and transported to the wellhead being maintained, which is a time consuming and costly step.